MSP430G2333: Microcontroller hangs and Does not boot when recovering from low voltage

Hi all,

I am working on a project that has MSP430G2333 .In normal cases the controller an the code runs fine but when I am testing multiple times and varying the Vcc from 1.2V-3.3V the controller sometimes hangs and does not respond as required. Firstly I thought there is problem in my code and checked the code thoroughly but can not find and potential reason for the hanging.

Then I wrote a simple program that turn on a LED attached to its GPIO pin when ever the MCU boots.(No peripherals like ADC,UART is enabled )

I am attaching the code here;

void main()
	{


 		WDTCTL = WDTPW + WDTHOLD;

 		__enable_interrupt();


		BCSCTL1 = 0x0F;                    // Set range
		DCOCTL = 0x70;                     // Set DCO step + modulation
		BCSCTL3 = 0x34;						//16MHZ


		_disable_interrupt();
		
		P1DIR|=BIT7;
		P1OUT|=BIT7;
		while(1);
}

the mention code run normally but the controller hangs sometime and does not response.